The answer is C. The program prints:
[43, 29, 16, 10, 8, 4]

Why?
sort() puts the list in order, smallest first. reverse=True flips it, so the biggest comes first. It changes the list itself.
The code again
scores = [4, 29, 10, 16, 43, 8]
scores.sort(reverse=True)
print(scores)
Try it: change one number in the program and predict the new output before you run it.